busybox/libbb/execable.c

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/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) 2006 Gabriel Somlo <somlo at cmu.edu>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
/* check if path points to an executable file;
* return 1 if found;
* return 0 otherwise;
*/
int execable_file(const char *name)
{
struct stat s;
return (!access(name, X_OK) && !stat(name, &s) && S_ISREG(s.st_mode));
}
/* search $PATH for an executable file;
* return allocated string containing full path if found;
* return NULL otherwise;
*/
char *find_execable(const char *filename)
{
char *path, *p, *n;
p = path = xstrdup(getenv("PATH"));
while (p) {
n = strchr(p, ':');
if (n)
*n++ = '\0';
if (*p != '\0') { /* it's not a PATH="foo::bar" situation */
p = concat_path_file(p, filename);
if (execable_file(p)) {
free(path);
return p;
}
free(p);
}
p = n;
}
free(path);
return NULL;
}
/* search $PATH for an executable file;
* return 1 if found;
* return 0 otherwise;
*/
int exists_execable(const char *filename)
{
char *ret = find_execable(filename);
if (ret) {
free(ret);
return 1;
}
return 0;
}
#if ENABLE_FEATURE_PREFER_APPLETS
/* just like the real execvp, but try to launch an applet named 'file' first
*/
int bb_execvp(const char *file, char *const argv[])
{
return execvp(find_applet_by_name(file) ? CONFIG_BUSYBOX_EXEC_PATH : file,
argv);
}
#endif